Improvement in fan-blowers



T. TVPRUSSER.

, Fan-Blowers. l No, 145,753, Patented Dec. 23,1873.

'UNITED STA'rEs TREAT T. FROSSER, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN FAN-BLOWERS.

Specification forming part ofLettel-s Patent No. 145,753, dated DecemberE23, 1873; application filed July 21, 1873.

To all whom it may concern:

Beit known that I, TREAT T. PRo'ssER, of Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Fan-Blowers, of which the following is a specification:

Figure l is a plan view of my improved blower, showing the cylindricalcase with the exhaust-aperture in the top thereof, the end rings withtheir journal-bearings, and a portion of the revolving spirally-bladedcylinder; and Fig. 2 is a sectional elevation, showing the manner ofattaching the end rings to the case,

the position of the spirallybladed cylinder within the case, and thejournals in their bearings.

Correspondin 0 letters denote corresponding parts in both of thefigures.

This invention relates to that class of machines which are termedfan-blowers 5 7 and it consists in the novel construction of its parts,and in their combination and arrangement, as will be more fullyexplained hereinafter.

In constructing blowers of this type, I use a cylindrical case, A, ofmetal orrof wood, of such diameter and length as may be necessary togive the blower the capacity required. The interior surface of thiscylindrical case is bored outfroin its ends inward for a short distance,in order that the cylinder which revolves within it may nearly touch itat these points. From the bored parts it is slightly increased in itsinterior diameter to near its center, where a considerable enlargementis made, as shown in FiO. 2 of the drawing, the object being to providea passage for the air after it has reached the center thereof, and allowit to pass to the eduction-aperture. Upon the outer surface of the case,and ateach of its ends, screw-threads are formed for the recep tion ofrings, which form supports for the same, its ends being open for thefree admission of air, while an opening is formed in its upper surfaceat its center for the escape of the same, which opening may be coveredwith a pipe for conducting the air to any desired locality. Rings B Bare screwed upon the ends of case A, said rings being provided with armsB1 B1, which extend from their outer edges toward their centers andterminate in a hub, B2, through which the shaft of the revolvof saidblades.

ing cylinder passes, said hub being, by preference, provided with achamber at or near its center for the reception of oil for lubricatingthe shaft. The outer surfaces of the lower arms are made to form a basefor the blower to stand upon, as shown, the spaces between such armsaffording room for the passage of air to the case. This method ofconstructing the case and its rings makes it certain that the aperturesin the hubs of the rings will always be in line with each other, as theyare bored in the lathe at the same time that the screw-threads upon theinterior surfaces of the rings are formed, and as no loose boxes arerequired there is no possibility of their becoming d-isarranged orgotten out of line, so as to cause an increase of friction or adisarrcngement of the other parts. Within the case A there is placed arevolving cylinder, C, which is provided upon each of its ends withspiral or screw-threaded blades, the outer diameters of which are suchas to cause them to fill the bored portions of the case, but allow themto turn freely therein. The outer ends of these blades are placed atpoints opposite to each other upon the end ofthe cylinder, and extendtherefrom to a point at or near its, center, where they meet and arejoined to those upon the opposite end, and at their juncture form achamber or space, C', into which the air is forced from each end of theblower, and from which it is forced by the converging surfaces As thereare two of these blades or threadsupon each end of the cylinder, itfollows that there are two separate and distinct air-passages from eachend of the cylinder, and two of the central chambers or spaces C', theybeing upon opposite sides of the cylinder, and so arranged that aportion of one of them is always opposite the eduction-aperture untilsome portion of the other is brought into the same relativeposition,which arrangement insures a steady blast of air from thcr casewhenever the cylinder is being rotated. The shaft uponwhich the cylinderC is mounted is designated by the letter D, it consisting of a round barof metal fitted within said cylinder and properly fastened thereto,havingjournals upon or near its outer ends, which are fitted into theapertures `in the hubs of the rings B B, and extending far enoughbeyond,

at one or both of its ends, to allow a pulley to be attached for givingmotion thereto, which motion may be derived from any prime mover.

Ihave contemplated giving' the spiral blades or the threads of thescrewr a gradually-increasing pitch from their outer ends to the pointswhere they meet at the center of the cylinder; but this form ofconstruction Will only be found necessary in cases Where it becomesdesirable to force the air out of the device under a greater pressurethan is ordinarily done With fanblowers, but in cases Where such anecessity arises this form of construction will be'found to eifect thedesired result.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, 1s-

l. A revolving cylinder for fan-blowers, havin g upon its periphery andat each of its ends spiral blades or screWAthreads, Which meet and arejoined at or near its center, thus forming; chambers, into which theoppositely-moving currents of air are forced, and from which it isexpelled by the j oint action of the two blades or threads,substantially as set forth.

2. The case A of a fan-blower, having open ends for the admission ofair, an interior diameter at its ends equal to the diameter of thecylinder, which revolves Within it, and an enl. rgement at its center,for the purpose of forming an air-chamber, substantially as set forth.

3. The end supports, consisting of a ring, B, for the reception of theends of the cylinder, arms B1 B1 B1, and a hub for the reception of theshaft, one of said arms forming the base upon which the machine rests,substantially as set forth.

4. The combination of the double-bladed cyl inder C, the open-ended caseA, and the end rings B, substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this speciiication in thepresence of two subscribing Witnesses.

B. EDW. J EILs, W. BRADFORD.

